This proposal seeks to support Dr. Shannon Mauszycki, a research speech-language pathologist in the VA Salt Lake City Health Care System in her aspirations to build a career as an independent VA research scientist. Apraxia of speech (AOS) is a treatable neurogenic speech disorder that is characterized by difficulties in sound production, reduced rate of speech, and disturbed prosody. Data regarding the prevalence of AOS are limited with no information regarding severity. Duffy (2005) found AOS was the primary diagnosis for 7.6% of 6101 cases of neurologic motor speech disorders. More recent data revealed AOS was the primary diagnosis for 12.2% of individuals with communication disorders, but AOS tends to occurs more frequently as a secondary communication disorder in conjunction with aphasia (Duffy, 2007). Effective treatment of a motor speech disorder such as AOS requires a thorough understanding of the physiological, perceptual, and acoustic characteristics of the disorder. A number of tools exist to examine physiologic aspects of articulation. Unfortunately, there have been a limited number of physiologic studies involving AOS conducted regardless of methodology. One method for examining the tongue's role in articulation is electropalatography (EPG). EPG involves the speaker wearing a pseudopalate, which is a custom made acrylic plate embedded with a varying number of electrodes that fits tightly against the upper palate. The electrodes detect tongue to palate contacts and allow contacts to be recorded, stored, and displayed in real time and is able to provide visual biofeedback to the speaker. EPG has had extensive application with a variety of speech disorders, such as those resulting from cleft palate, hearing impairment, and developmental speech delay (Carter et al., 2004; Dagenais, 1992, 1995; Fletcher et al., 1991; Gibbon et al., 2001). Investigators have used the tongue to palate displays to provide visual biofeedback to improve sound production. To date, there has been limited utilization of EPG with AOS, although preliminary investigations have yielded promising findings in a few case study reports in terms of describing as well as improving disordered articulation. Experimental data concerning the efficacy of EPG treatment for AOS are currently unavailable. The initial purpose of this research is to examine the impact of repeated measurement over time on EPG and perceptual speech measures in speakers with AOS. In order to appropriately evaluate the effects of treatment, it is critical to understand the stability of these measures over time and with repeated exposure with disordered speakers. The second purpose of this research is to systematically examine the effects of EPG treatment as a means of visual biofeedback for speakers with AOS.